No-voltage release attachment for electric switches



G. A. BURNHAM.

NO-VOLTAGE RELEASE ATTACHMENT FOR ELECTRIC SWITCHES.

0 91 n 2 m MU. MU E M2 H m P a m 0w rm E D D u N 0 H A m H P A 1 6 9 IQ 3 4 3 1 n u E 'lk'fizesa G. A. BURNHAM.

NO-VOLTAGE RELEASE ATTACHMENT FOR ELECTRIC SWITCHES.

' APPLICATION FILED DEC. 9. 1916.

1 ,343, 96 1 Patente J 1111 22, 1920;

2 SHEETS-SHEET 2.

UNITED STATES GEORGE A. BURNHAM, orsnuens, MASSACHUSETTS, ASSIGNOR TO snAns :B.

coivmr, JR, or BROOKLINE, MASSACHUSETTS.

To all whom it may 00mm: I

Be it known that I, Gnonen A. BURN? HAM, a citizen of the United States, residing at Saugus, in the county of Essex and State of lVl-assachusetts, have invented an Improvement in No-Voltage Release Attachments for Electric Switches, of which the following is a specification; 1

This invention relates to no-voltage release attachments for electric switches,

which may be used in connection with a through normal position to running position, and suitable means is provided for controlling said operating-element, which acts to hold it in normal position, and permit movement thereof into starting position, and also permit movement thereof 7 from starting position into running position, in

case said latter movement is quickly performed, otherwlse, it will be engaged whenv passing through normal position, and its movement arrested.

The operating-element is usually held by hand in. starting position, preparatory to being moved into running position, but means are provided for holding it in running position. I r

A no-voltage release attachment embodying my invention is adapted to have as a component part of it a trippingmeans which may be applied to a motor-starting switch and arranged to be set by the operating element of the motor starting switch when moved into running position to hold said-j element in, such position, and which tripping means, when operated, will release.

said element and permit it to return, automatically, to normal position; and said at.- tachmentalsa includes as a component part of it an electroi-magnetic device, such for:

instance as an alternating current solenoid,

as for example, such as is, shown in. my Patent #1266917, dated, May 21, 19,18,

adapted to have said tripping-meansso. as-

sociated with it that said means may be operated by the solenoid or by hand, to trip the operating element of the switch and permit it to resume its normal position.

Specification of Letters Patent. Patented June "Application filed December 9. 1916. Serial No. 136,096.

PAT NT OFFICE".

:No-voL'rAeE RELEASE ATTACHMENT r03 nrnc'rmo SWITCHES.-

Figure I is a plan view of a no-voltage;

release attachment embodying my inven The motor-starting switch here shown for the purpose of illustrating my invention, is substantially the same as shown .in my aforesaid Patent #1,312,777, and consists of a double-throw switch having a' movable switch element 40,. normally arranged between two stationary switch elements 26, 26, and adapted to be moved into engagement with one of said elements to start the motor and into engagement with the other element to cause the motor to run. represents the operating element for said movable switch element, which is secured to a shaft 52; and 61 represents a latch adapted for controlling the movement of said operating element, said latch having a shallow recess in oneedge, intermediate its lengtlnadapted to r.eceive a pin 60, on the. operating element'- when the operating element is in its neutral or open circuit position. Said operating element is, movable in a direction toward the right from neutral or open cirraiit position through and against a stop 57, to move the movable switch element into engagement with one of the stationary switch elements 26, to close the circuit and cause, the motor to start, and is movable in a direction toward. the left, through neutral, and: against a pin 56, to move the movable switch element into engagement with the other stationary switch element to close the circuit, and cause the motor to run; although such latter movement must be made quickly, particularly when passing through neutral, to prevent the latch which, at such time, ismovi-ng downwardly by gravity, from engaging and arresting it.

In the switch, as here shown, when the operating element is moved into running position it will not be locked the crank shaft due to the relative position; thereof at such time, as in my said application, and hence will return to neutral unless means are provided for holding itin running position,

and herein my novel 110-voltage releasing attaclnnent is adapted to accomplish this result.

The no-volt releasing attachment, as here shown, consists essentially oi a solenoid, substantially as shown in my Patent #l,266,9l7, having a movable core-piece 25, a stem 25 attached thereto, and extending upward through a hole in a top core-piece 15, and is movable longitudinally therein, and said stem has at its upper end a head 28. lVhen the current flows through the winding of the solenoid, its movable corepiece 25 is moved into attracted position, and the stem is moved verti ally in an upward direction, and the head is raised to an elevated position above the top of: the solenoid, and when the flow of current ceases or drops below a predetermineo value, the movable core-piece falls, and the head on the stem will correspondingly move downward.

Tripping means for the switch is adapted to be associated with said solenoid, and, as here shown, said means consists oil a trip ping-lever 70, pivoted at 71, to a fixed point on the switch frame, and extended laterally through the side wall of the switch case, and having its outer end-portion 72 bifurcated to receive the stem 25, on the movable corepicce of the solenoid, at a point below the head 28.

A spring 75 is arranged on the pivot of the tripping lever having a normal tendency to lift said lever. Said lever has a notch or recess 7 6 with a shoulder 77 at one side adapted to receive the end of a dog 78, which is fixed to the shaft 52 of the operating element and movable rotatably therewith. Said dog, however, does not engage the tripping lever when the operating element is in neutral position, as represented in Fig. 3, or in starting position, as represented in Fig. 4-, but when said element is moved into running position, see Fig. 2, it will engage the tripping lever and depress it sufliciently to enable it to enter the recess therein and engage the shoulder, whereupon said lever will be held depressed by the dog and will act to hold the dog and consequently the operating element in running position. Upon depression of said lever the dog will be disen aged and the operating element thereby released and permitted to return to neutral position, which it will do by gravity or any other force which may be utilized for the purpose.

As the outer end of the tripping lever is arranged below the head 28, connected with the movable core-piece of the solenoid, it will be seen that when said head is permitted or caused to move downward, the trip-- ping lever will be depressed and caused to disengage the dog.

In operation, when the switch is open, the solenoid will be deenergized and its corepiece moved downward into its lowermost position; and when the operating element is moved from neutral into motor-starting position, said element and also the dog being moved in a direction toward the right from neutral, see Fig. i, the solenoid will. become energized and its core-piece will be eievated, and the head correspondingly liited so that the tripping lever will be held in elevated position by its lifting spring, and when the operating element is moved into running position, see Fig. 2, the dog will be moved into engagement with the tripping lever, and the operating element will become locked in running position.

\Vhen it is desired to open the switch manually, the head 28 may be engaged and depressed by hand, and the tripping lever will be likewise depressed, thus disengaging the dog and permitting the operating element to resume its normal or open circuit position; or while the operating element is locked in running position, and the voltage should drop, the head 28 will be moved downward, and the tripping lever correspondingly moved to disengage the dog and release the operating element, permitting it to return to normal or open circuit position.

I claim 1. A 110-voltage release attachment for electric switches comprising a solenoid hav ing attaching means for attachment to the switch casing, and a core movable therein engageable with a tripping-lever, a trippii'ig-lever having core-engaging means at one end and a pivot hole at the other end for pivotal connection with the switch casing, and a notch intermediate its ends, and a dog having shaft-engaging means for attachment to the operating shaft for the switch, and a portion engageable with the notch in' said tripping-lever.-

2. The combination with an electric switch comprising an inelosing casing having a slot therein, and a switch. operating shaft and stationary and movable switch members disposed therein, of a dog having a shaft-receiving portion secured to said shaft and a projecting-portion, a trippinglever disposed within said casing having a pivot-hole at one end thereof and a dog holding notch intermediate its ends, a pivot pin extended through said hole and secured. to said casing, said trippingdever extended without said casing through the slot therein and terminating in a core-engaging portion, a solenoid having casing engaging means secured to the exterior of said casing in proximity to the slot therein and a core movable in said solenoid having means for engagement with the extended end of said tripping-lever.

3. The combinaton with an electric switch comprising an inclosing casing having a slot in the upper part thereof, a switch operating shaft disposed in the upper part, and stationary and movable switch members disposed in the lower part thereof, of a dog having a shaft-receiving portion and a pro jecting portion, a trippinglever disposed within said casing beneath, and'in proximity to, said shaft having a'pivot hole in one end thereof and a notch intermediate its ends to receive the projecting portion of said dog, a pivot pin passed through said pivot hole and secured to said casing, said tripping-lever having its other end extended without said casing through the slot therein and terminating in a core-engaging portion, a solenoid having casing engaging means secured to the exterior of said casing below, and in proximity to, the extended end of said lever, and a core movable in said solenoid having tripping-lever engaging-means.

4. A no-voltage release attachment for motor-starting switches comprising tripping means for the switch, consisting of a dog having lever-engaging means adapted to be fixed to the shaft of the operating element of the switch, a spring-controlled tripping-lever having dog-engaging means, said lever extended outward through the side wall of the switch case, a solenoid arranged to be supported by the switch case, and a movable solenoid core-piece having a stem with a head thereon, the extremity of the tripping-lever being bifurcated to receive said stem below the head and be engaged by the head to admit of the tripping lever being moved by the downwardly moving'core-piece, and. also independently of the core-piece.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

GEORGE A. BURNHAM. Witnesses:

Grms'rnn D. AINsWoR'rH, HAROLD S. RAMsAY. 

